Method and Apparatus for Manufacturing Hydrogen-Containing Gas

ABSTRACT

There is provided a technique for manufacturing a hydrogen-containing gas. An oxygen-containing gas is mixed with a feed gas obtained by mixing steam with a hydrocarbon fuel, this mixture is introduced into a catalytic reaction chamber, and a partial oxidation reaction and a steam reforming reaction are conducted to obtain a hydrogen-containing gas. In this reforming, an antechamber of the catalytic reaction chamber is heated up to a self-ignition temperature in a first catalyst section, where the self-ignition temperature is the temperature at which a mixed gas self-ignites during the advection period required for the mixed gas to move from a mixing chamber to the catalytic reaction chamber, with this temperature being at least a minimum partial-oxidation temperature and lower than a minimum steam reforming temperature.

TECHNICAL FIELD

The present invention relates to a method for manufacturing ahydrogen-containing gas, comprising a mixing step of mixing, in a mixingchamber, an oxygen-containing gas with a feed gas obtained by mixingsteam with a hydrocarbon fuel, and a reformation step of guiding themixed gas obtained in the mixing chamber into a catalytic reactionchamber via an antechamber provided on the upstream side of thecatalytic reaction chamber, and bringing the mixed gas into contact witha reforming catalyst and thereby obtaining a hydrogen-containing gas bymeans of a partial oxidation reaction and a steam reforming reaction,and relates to a manufacturing apparatus that makes use of this kind ofmethod for manufacturing a hydrogen-containing gas.

BACKGROUND ART

A hydrogen-rich gas can be obtained by utilizing a catalytic reaction toreform a hydrocarbon fuel as a feed gas for FT (Fischer-Tropsch)synthesis, methanol synthesis, or ammonia synthesis, for example.Partial oxidation reactions and steam reforming reactions are known ascatalytic reformation reactions of this kind for hydrocarbon fuels. Theabove-mentioned partial oxidation reaction proceeds according to thechemical formula given as Chemical Formula 1 below, and is what is knownas an exothermic reaction.

C_(n)H_(2n+2)+0.5nO₂→(n+1)H₂ +nCO (exothermic reaction)  [ChemicalFormula 1]

The above-mentioned steam reforming reaction proceeds according to thechemical formula given as Chemical Formula 2 below, and is what is knownas an endothermic reaction.

C_(n)H_(2n+2) +nH₂O→(2n+1)H₂ +nCO (endothermic reaction)  [ChemicalFormula 2]

Therefore, a partial oxidation reaction and a steam reforming reactioncan both be brought about by proper selection of the reforming catalyst.The partial oxidation reaction can be brought about on the pre-stageside of the catalytic reaction chamber, and the heat thereof can beutilized to bring about partial oxidation and steam reformation on thepost-stage side of the catalytic reaction chamber.

In view of this, it has been proposed that a hydrogen-rich gas can beobtained by mixing steam and a hydrocarbon fuel to obtain a feed gas,mixing an oxygen-containing gas (such as pure oxygen) with this feedgas, subjecting the mixed gas thus obtained to a partial oxidationreaction on the pre-stage side of a catalyst layer, raising thetemperature of the reaction gas to the temperature required for a steamreforming reaction, and mainly bringing about a steam reforming reactionon the post-stage side of the catalyst layer.

This reforming technology is called autothermal reformation, in which aseries of reactions (the reactions of Chemical Formulas 1 and 2) occurat the same time.

With this kind of reformation, when a single reaction chamber is usedfor the catalytic reaction chamber filled with the reforming catalyst,the temperature begins to rise near the inlet of the catalytic reactionchamber, and the temperature rises steadily downstream, reaching thepeak temperature. After this, the temperature settles down to anequilibrium temperature that is determined by the inlet temperature, theinlet gas composition, and the reaction pressure.

The technology disclosed in Patent Document 1 is known as this kind ofautothermal technology.

With the technology disclosed in Patent Document 1, as discussed in theClaims of the Specification thereof, there is proposed “a hydrogengenerating apparatus for generating hydrogen by bringing a raw materialcontaining a hydrocarbon compound, water, and air into contact with areforming catalyst body, wherein the reforming catalyst body isconstituted by two stages, a reforming catalyst containing at leastplatinum or rhodium is disposed in the pre-stage, a reforming catalystcontaining at least ruthenium or rhodium is disposed in the post-stage,and the reforming catalyst in the pre-stage and the reforming catalystin the post-stage are made up of mutually different elements.

When this proposed constitution is employed, a reaction including steamreformation can be conducted after a partial oxidation reaction isbrought about by the reforming catalyst on the pre-stage side and thetemperature has reached a specific region.

Patent document 1: JP 2002-121007A (Claims)

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

In this conventional technique, however, there has been no debatewhatsoever about the state of the non-catalyst portion located upstreamfrom the catalytic reaction chamber.

The non-catalyst portion located upstream from the catalytic reactionchamber is called the antechamber in this application; since thereaction that occurs near the inlet of the catalytic reaction chamber isan exothermic reaction, the temperature at this portion can rise quitehigh. Therefore, the temperature is also quite high at the outletportion of the antechamber (the portion linked to the inlet into thecatalytic reaction chamber). If we here consider the gas that reachesthis portion, we see that the gas at this portion is a mixed gas thatresults from oxygen being mixed into feed gas that is a mixture of steamand a hydrocarbon fuel, and because oxygen and hydrocarbon fuel arecontained, there is the potential for self-ignition. If self-ignitionshould occur at this site, soot will be generated and the gastemperature will be abnormally high, among other problems, which causesthe inside of the antechamber to be in an unstable state, and theantechamber and catalytic reaction chamber cannot be kept in a goodoperating state.

The present invention was conceived in light of the above situation, andit is an object thereof to provide a method for manufacturing ahydrogen-containing gas, with which a hydrogen-containing gas isobtained by means of a partial oxidation reaction and a steam reformingreaction, wherein an antechamber provided on the upstream side of acatalytic reaction chamber is in a stable state, and to provide amanufacturing apparatus that makes use of this method.

Means for Solving Problem

The characteristic constitution of the method for manufacturing ahydrogen-containing gas, for achieving the stated object, by executing amixing step of mixing, in a mixing chamber, an oxygen-containing gaswith a feed gas obtained by mixing steam with a hydrocarbon fuel, and areformation step of guiding the mixed gas obtained in the mixing chamberinto a catalytic reaction chamber via an antechamber provided on theupstream side of the catalytic reaction chamber, and bringing the mixedgas into contact with a reforming catalyst and thereby obtaining ahydrogen-containing gas by means of a partial oxidation reaction and asteam reforming reaction, is as follows.

Specifically, the catalytic reaction chamber includes a first catalystsection in which is disposed a first reforming catalyst that has goodlow-temperature oxidation activity, and a second catalyst section whichis provided on the downstream side of the first catalyst section and inwhich is disposed a second reforming catalyst that has good reformingactivity, and the mixed gas is introduced into the catalytic reactionchamber after the temperature of the antechamber has been set to atleast a minimum partial-oxidation temperature and below a self-ignitiontemperature, where the self-ignition temperature is the temperature atwhich the mixed gas self-ignites during the advection period requiredfor the mixed gas to move from the mixing chamber to the catalyticreaction chamber, and the minimum partial-oxidation temperature is theminimum temperature at which the first reforming catalyst undergoes thepartial oxidation reaction.

With this method, the catalyst in the catalytic reaction chamber isdivided into a first reforming catalyst and a second reforming catalyst,the first reforming catalyst, which has good low-temperature oxidationactivity, is disposed on the inlet side, and the second reformingcatalyst, which has good reforming activity, is disposed downstream fromthe first reforming catalyst. As for the part from the antechamber tothe first reforming catalyst, the mixed gas reaches the inlet of thecatalytic reaction chamber at a temperature that is below theself-ignition temperature but at least as high as the minimumpartial-oxidation temperature.

As a result, at this antechamber portion, the partial oxidation reactioncan be commenced by the first reforming catalyst after the gas hasreliably reached the catalytic reaction chamber inlet, without causingany self-ignition, so instability in the state of the antechamber can beproactively avoided.

Furthermore, since the first reforming catalyst has good low-temperatureoxidation activity, its catalytic reaction occurs even at relatively lowtemperatures. As a result, even if the temperature of the mixed gas inthe antechamber is relatively low (below the self-ignition temperature),a partial oxidation reaction will proceed at the stage when the gas hasbeen introduced into the catalytic reaction chamber, so the state of themixed gas in the antechamber can be kept stable while the reaction isproperly brought about at the catalytic reaction chamber inlet.

The first reforming catalyst described above as having goodlow-temperature oxidation activity can be a reforming catalyst thatcontains at least one of ruthenium and platinum, while the secondreforming catalyst that has good reforming activity can be a reformingcatalyst that contains at least one of nickel, rhodium, and ruthenium.

The characteristic constitution of the hydrogen-containing gasmanufacturing apparatus that makes use of this method, which comprises amixing chamber in which an oxygen-containing gas is mixed with a feedgas obtained by mixing steam with a hydrocarbon fuel, and a catalyticreaction chamber into which the mixed gas obtained in the mixing chamberis guided via an antechamber, and in which the mixed gas is brought intocontact with a reforming catalyst, and a hydrogen-containing gas isobtained by means of a partial oxidation reaction and a steam reformingreaction, is such that the catalytic reaction chamber comprises, fromthe inlet side, a first catalyst section in which is disposed a firstreforming catalyst that has good low-temperature oxidation activity, anda second catalyst section which is provided on the downstream side ofthe first catalyst section and in which is disposed a second reformingcatalyst that has good reforming activity, and said apparatus comprisesantechamber temperature setting means for setting the temperature of theantechamber to at least a minimum partial-oxidation temperature andbelow a self-ignition temperature, where the self-ignition temperatureis the temperature at which the mixed gas self-ignites during theadvection period required for the mixed gas to move from the mixingchamber to the catalytic reaction chamber, and the minimumpartial-oxidation temperature is the minimum temperature at which thefirst reforming catalyst undergoes the partial oxidation reaction.

With the above-mentioned hydrogen-containing gas manufacturing method,it is preferable if the first reforming catalyst concentration of thefirst catalyst section is the concentration at which a first catalystsection outlet temperature is no higher than the self-ignitiontemperature and is at least the temperature at which the second catalystundergoes partial oxidation, in a state in which the temperature of theantechamber has been set to at least the minimum partial-oxidationtemperature and below the self-ignition temperature.

With a hydrogen-containing gas manufacturing apparatus that makes use ofthis method, the first reforming catalyst concentration of the firstcatalyst section is the concentration at which a first catalyst sectionoutlet temperature is no higher than the self-ignition temperature andis at least the temperature at which the second catalyst undergoespartial oxidation, in a state in which the temperature of theantechamber has been set to at least the minimum partial-oxidationtemperature and below the self-ignition temperature.

The role of the first reforming catalyst in this application is to raisethe temperature of the mixed gas to the temperature at which the secondreforming catalyst induces an oxidation reaction. Meanwhile, the firstreforming catalyst outlet temperature is determined mainly by the inlettemperature of the catalytic reaction chamber, the heat generated bypartial oxidation at the first catalyst section, and the heattransmitted from the second catalyst section. In view of this, with thismethod, the temperature at the first catalyst section, which has goodlow-temperature oxidation activity, is raised high enough for the secondreforming catalyst to induce a partial oxidation reaction, while thecatalyst combustion is utilized. Even though we refer here to thetemperature at which the second reforming catalyst can undergo partialoxidation, there is still a restriction that the temperature be nohigher than the self-ignition temperature.

With this structure, oxidation of the mixed gas by the second reformingcatalyst substantially begins at and proceeds from near the boundarybetween the first catalyst section and the second catalyst section (andespecially near the inlet of the second catalyst section). That is,conventional partial oxidation and steam reforming can proceed at thesecond catalyst section, while the first catalyst section serves as afunctional site that suitably sets the starting point for the partialoxidation and steam reforming that proceed at the second catalystsection.

When this structure is employed, a heat blocking layer with lowerthermal conduction characteristics than the first catalyst section ispreferably provided between the first catalyst section and the secondcatalyst section.

That is, the apparatus for manufacturing a hydrogen-containing gas canbe such that a heat blocking layer with lower thermal conductioncharacteristics than the first catalyst section is provided between thefirst catalyst section and the second catalyst section.

As described above, the first catalyst section outlet temperature isdefined as being no higher than the self-ignition temperature and atleast the temperature at which the second catalyst undergoes partialoxidation. Meanwhile, near the inlet to the second catalyst section,partial oxidation by the second catalyst section proceeds and thetemperature quickly rises to the level at which steam reforming ispossible, after which the peak temperature is reached, and then theequilibrium temperature is reached, which is lower than the peaktemperature. Here, when the second catalyst has high activity, thereaction from the temperature at the second catalyst section inlet tothe peak temperature occurs extremely rapidly, and the peak temperatureis sometimes reached near the inside of the second catalyst sectioninlet. In this situation, the effect of the peak temperature tends to belinked to higher temperature on the upstream side, and when the firstand second catalyst sections are integrated, there is the risk that thepeak temperature location will shift toward the first catalyst sectionside, creating an unstable situation.

In view of this, a heat blocking layer is provided between the firstcatalyst section and the second catalyst section. Providing this heatblocking layer makes it possible to suppress heat transfer from thesecond catalyst section to the first catalyst section outlet side, whichis lower in temperature than in the second catalyst section, and as aresult, the predetermined temperature for the first catalyst sectionoutlet (a temperature no higher than the self-ignition temperature andat least the temperature at which the second catalyst undergoes partialoxidation) can be stably maintained.

An inert member that has no catalytic activity is preferably mixed withthe first catalyst section to set the first reforming catalystconcentration.

In this application, a catalyst that has good low-temperature oxidationactivity is used as the first reforming catalyst, but it is necessary toconfine the location where the peak temperature appears as discussedabove to the second catalyst section. Specifically, it is necessary tokeep the amount of heat generated by the first catalyst section to alevel that will result in a suitable temperature at the outlet from thissection. In view of this, an inert member can be mixed with the firstcatalyst section, and the amounts of the first reforming catalyst andthe inert member (the first reforming catalyst concentration) adjusted,so as to adjust the first catalyst section outlet temperature to thetargeted temperature in this application.

It is also preferable in this configuration is the first catalystsection outlet temperature is the self-ignition temperature.

When a hydrogen-containing gas manufacturing apparatus is in its normaloperating state, the above-mentioned first catalyst section outlettemperature is the above-mentioned self-ignition temperature.

By thus having the first catalyst section outlet temperature be theself-ignition temperature, the second catalyst section inlet temperatureis set as high as possible, and the partial oxidation reaction and steamreforming reaction conducted in the second catalyst section are broughtabout rapidly near the second catalyst section inlet, and the firstcatalyst section can be used favorably.

At this point, oxygen substantially remains behind as indicated by theone-dot chain line in FIG. 3. Therefore, if ruthenium, which has goodoxidation activity, is provided at the inlet to the second catalystsection where the reforming reaction substantially starts, oxygen willbe present at high temperature, which tends to lead to a problem in thatthe ruthenium is degraded or scattered.

This is dealt with in the constitution of this application by having thefirst catalyst section, with its restriction to be no higher than theself-ignition temperature, be at an even lower temperature, although thetemperature has a tendency to rise. As a result, no problems withdegradation, scattering, or the like are encountered even thoughruthenium is used at this site. Specifically, ruthenium, which has goodlow-temperature oxidation activity, can be used effectively andfavorably.

In the constitution described up to this point, it is preferable thatthe temperature of the mixed gas flowing through the antechamber ismaintained higher than a minimum antechamber temperature and lower thana maximum antechamber temperature, where the minimum antechambertemperature is the temperature that is higher between the minimumpartial-oxidation temperature and the dew point temperature of the mixedgas, and the maximum antechamber temperature is the self-ignitiontemperature.

Steam is mixed into the mixed gas used in the hydrogen-containing gasmanufacturing method according to the present invention, and the dewpoint of this steam poses a problem. As the reforming reactionapproaches the minimum temperature at which partial oxidation can occur,condensation may occur depending on the state of the mixed gas. Ifcondensation occurs, it will hamper the catalytic reaction, and good gasflow cannot be ensured. In view of this, a good operating state can bemaintained by taking into account the dew point temperature in relationto the mixed gas state, and ensuring the proper mixed gas state in theantechamber.

With a hydrogen-containing gas manufacturing apparatus of thisconstitution, the temperature of the mixed gas flowing through theantechamber is maintained higher than a minimum antechamber temperatureand lower than a maximum antechamber temperature, where the minimumantechamber temperature is the temperature that is higher between theminimum partial-oxidation temperature and the dew point temperature ofthe mixed gas, and the maximum antechamber temperature is theself-ignition temperature.

With the hydrogen-containing gas manufacturing method described up tothis point, it is preferable if the sulfur compound concentration of thehydrocarbon fuel is 1 ppb or less.

As the sulfur oxide compound concentration rises in the hydrocarbonfuel, the peak temperature of the reaction that occurs in the catalyticreaction chamber has a tendency to rise. If the reforming catalyst isruthenium, keeping the sulfur compound concentration to 1 ppb or lessallows the peak temperature inside the catalytic reaction chamber to bea temperature at which a stable reaction can be obtained. The amounthere only needs to be 1 ppb or less, and there is no lower limitthereof. Lowering this concentration also avoids degradation of thereforming catalyst.

Ruthenium is known as a catalyst that has good low-temperature oxidationactivity and good reforming activity, but when ruthenium is used indifferent concentrations for both the first and second catalysts in thisapplication, it can be used as follows.

Specifically, as a hydrogen-containing gas manufacturing methodincluding a mixing step of mixing, in a mixing chamber, anoxygen-containing gas with a feed gas obtained by mixing steam with ahydrocarbon fuel, and a reformation step of guiding the mixed gasobtained in the mixing chamber into a catalytic reaction chamber via anantechamber provided on the upstream side of the catalytic reactionchamber, and bringing the mixed gas into contact with a reformingcatalyst and thereby obtaining a hydrogen-containing gas by means of apartial oxidation reaction and a steam reforming reaction, the catalyticreaction chamber includes a first catalyst section in which is disposeda ruthenium catalyst, and a second catalyst section which is provided onthe downstream side of the first catalyst section and in which isdisposed a ruthenium catalyst, in a state of higher concentration thanin the first catalyst section, and the mixed gas is introduced into thecatalytic reaction chamber after the temperature of the antechamber hasbeen set to at least a minimum partial-oxidation temperature and below aself-ignition temperature, where the self-ignition temperature is thetemperature at which the mixed gas self-ignites during the advectionperiod required for the mixed gas to move from the mixing chamber to thecatalytic reaction chamber, and the minimum partial-oxidationtemperature is the minimum temperature at which the first reformingcatalyst undergoes the partial oxidation reaction, and the rutheniumcatalyst concentration of the first catalyst section is set to theconcentration at which a first catalyst section outlet temperature is nohigher than the self-ignition temperature and is at least thetemperature at which the second catalyst undergoes partial oxidation, ina state in which the temperature of the antechamber has been set to atleast the minimum partial-oxidation temperature and below theself-ignition temperature, and a heat blocking layer with lower thermalconduction characteristics than the first catalyst section is providedbetween the first catalyst section and the second catalyst section.

In this case, the hydrogen-containing gas manufacturing apparatus can beone that comprises a mixing chamber in which an oxygen-containing gas ismixed with a feed gas obtained by mixing steam with a hydrocarbon fuel,and the catalytic reaction chamber into which the mixed gas obtained inthe mixing chamber is guided via an antechamber, in which the mixed gasis brought into contact with a reforming catalyst, and ahydrogen-containing gas is obtained by means of a partial oxidationreaction and a steam reforming reaction, wherein the catalytic reactionchamber comprises, from the inlet side, a first catalyst section inwhich is disposed a ruthenium catalyst, and a second catalyst sectionwhich is provided on the downstream side of the first catalyst sectionand in which is disposed a ruthenium catalyst in a state of higherconcentration than that in the first catalyst section, and saidapparatus comprises antechamber temperature setting means for settingthe temperature of the antechamber to at least a minimumpartial-oxidation temperature and below a self-ignition temperature,where the self-ignition temperature is the temperature at which themixed gas self-ignites during the advection period required for themixed gas to move from the mixing chamber to the catalytic reactionchamber, and the minimum partial-oxidation temperature is the minimumtemperature at which the first reforming catalyst undergoes the partialoxidation reaction, and the ruthenium catalyst concentration of thefirst catalyst section is the concentration at which a first catalystsection outlet temperature is no higher than the self-ignitiontemperature and is at least the temperature at which the second catalystundergoes partial oxidation, in a state in which the temperature of theantechamber has been set to at least the minimum partial-oxidationtemperature and below the self-ignition temperature, and a heat blockinglayer with lower thermal conduction characteristics than the firstcatalyst section is provided between the first catalyst section and thesecond catalyst section.

When ruthenium alone is used as above, as has already been described, aninert member that has no catalytic activity can be mixed into the firstcatalyst section to adjust its ruthenium concentration.

Also, the problem of condensation can be solved by keeping thetemperature of the mixed gas flowing through the antechamber below amaximum antechamber temperature and higher than a minimum antechambertemperature, where the minimum antechamber temperature is thetemperature that is higher between the minimum partial-oxidationtemperature and the dew point temperature of the mixed gas, and themaximum antechamber temperature is the self-ignition temperature.

BEST MODE FOR CARRYING OUT THE INVENTION

A hydrogen-containing gas manufacturing apparatus 1 according to thepresent invention will now be described through reference to thedrawings.

GTL Manufacturing Process

FIG. 1 shows the configuration of a GTL (Gas-To-Liquid) manufacturingprocess 3 in which the hydrogen-containing gas manufacturing apparatus 1according to the present invention is provided on the upstream side ofan FT synthesis reactor (labeled FT reactor in the drawings) 2 in whichone of the feed gases is a hydrogen-containing gas. As shown in thedrawing, this system 3 comprises the hydrogen-containing gasmanufacturing apparatus 1 of the present invention provided upstreamfrom the FT synthesis reactor 2; a hydrocarbon fuel f (such as naturalgas), steam s, and oxygen o (the oxygen-containing gas) are supplied tothe hydrogen-containing gas manufacturing apparatus 1 and reformed,after which hydrogen-rich gas h is sent to the FT synthesis reactor 2.

In addition to the above-mentioned natural gas, the hydrocarbon fuel canbe a gaseous alcohol, ether, LPG, naphtha, gasoline, kerosene, lightoil, heavy oil, asphaltene oil, oil-sand oil, liquefied coal oil, shaleoil, waste plastic oil, biofuel, or the like.

The system of processing the hydrocarbon fuel f will now be described.The hydrocarbon fuel f is desulfurized to 1 ppb or less in adesulfurization apparatus 4, after which steam s is added to obtain whatis called the feed gas f1 in the present invention. Oxygen o is furthermixed as an oxygen-containing gas into the feed gas f1 as shown in FIG.1, and this mixture is introduced into a single catalytic reactionchamber 5. In this catalytic reaction chamber 5 is disposed a reformingcatalyst c1 capable of subjecting the mixed gas f2 (obtained by mixingthe hydrocarbon fuel f, steam s, and oxygen o) to an autothermalreforming reaction. In this catalytic reaction chamber 5, mainly apartial oxidation reaction occurs on the inlet side, and mainly a steamreforming reaction occurs downstream from this location.

Specific, favorable examples of this kind of reforming catalyst includeruthenium, platinum, nickel, rhodium, and other noble metal catalysts.In a first embodiment, however, ruthenium and platinum are used as afirst reforming catalyst c1 a with good low-temperature oxidationactivity, and nickel and rhodium are used as a second reforming catalystc1 b with good reforming activity. The reason for thus dividing thereforming catalyst c1 into two groups is that in this application, inorder to make the temperature of the mixed gas inside the antechamber 9below the self-ignition temperature T3, the increase from thetemperature inside the antechamber 9 to the temperature at which thesecond reforming catalyst can perform oxidation is brought about by thefirst reforming catalyst c1 a, so that the state of the antechamber 9can be stabilized as much as possible.

Meanwhile, in a second embodiment, ruthenium is used as a firstreforming catalyst d1 with good low-temperature oxidation activity, andis also used as a second reforming catalyst d1 with good reformingcatalyst. The reason for thus treating ruthenium as both the firstreforming catalyst and the second reforming catalyst is that experimentsand investigations by the inventors have revealed that good, stableoperation is possible at a relatively low peak temperature whenruthenium is used in different concentrations for the first catalystsection and the second catalyst section in a system in which partialoxidation and steam reforming are performed.

These catalysts may be in any shape, and there are no restrictions oncarriers, but it is preferable to use a carrier whose main component isone selected from among alumina, zirconia, silica, titania, magnesia,and calcia. Preferably, the catalyst is supported on a carrier, and usedin the molded form of tablets, spheres, or rings, or in a honeycombshape.

If a typical example of the manufacture of this kind of catalyst isdescribed for when ruthenium is supported on an alumina carrier, forexample, the catalyst can be prepared in the following manner: aspherical alumina carrier (4 to 6 mm) is immersed in a rutheniumchloride aqueous solution and dried for 2 hours at 80° C. in air, afterwhich it is fixed (with an NaOH aqueous solution), reduced (withhydrogen), washed (at a temperature of 90° C.), and dried (left at 80°C. in air).

If a case of supporting platinum, nickel, and rhodium on an aluminacarrier is described, the catalyst can be prepared by usingchloroplatinic acid, rhodium nitrate, nickel nitrate, and rhodiumchloride instead of the above-mentioned ruthenium chloride, and bybaking for 1 hour at 650° C.

The supported percentage can be 3.0 wt %, for example, for which thecatalyst may be dispersed in a 30 wt % (as silica) colloidal silicasolution to create a catalyst slurry, and this catalyst slurry may besupported in a cordierite honeycomb with 400 cells, a diameter of 24 mm,and a length of 2 cm. These are dipped in the catalyst slurry and backedin air for 1 hour at 500° C. The supported amount is 3 g of noble metalper cubic decimeter (liter) of honeycomb volume.

In the second embodiment discussed below, the supported percentage isset to a value lower than 3.0 wt %.

In this application, a good autothermal reforming reaction is producedin the catalytic reaction chamber 5 by having the mixed gas f2introduced favorably into the catalytic reaction chamber 5. What isimportant for producing a “good reaction” here is that the partialoxidation reaction is brought about first near the inlet 5 a, and thatno carbon is generated inside the catalytic reaction chamber 5.Furthermore, “good reaction” means that the state (and particularly thetemperature state) of the mixed gas f2 at the inlet 5 a of the catalyticreaction chamber 5 is suitably controlled, so that the state inside thereaction chamber makes a suitable transition from a state of justpartial oxidation to a state of partial oxidation that includes steamreforming.

As shown in FIG. 1, the catalytic reaction chamber 5 is disposed in thevertical direction, the feed gas f1 (a gas obtained by mixing the steams with the hydrocarbon fuel f) is supplied from the top side, a mixedgas f2 into which the oxygen o has been mixed is introduced from theinlet 5 a provided on the upper side of the catalytic reaction chamber5, the reforming reaction is concluded, and the hydrogen-rich gas h issent from under the catalytic reaction chamber 5 toward the FT synthesisreactor 2.

In this application, a first embodiment and a second embodiment aregiven as examples of the hydrogen-containing gas manufacturing apparatus1.

First Embodiment

The specific constitution of the hydrogen-containing gas manufacturingapparatus 1 of this embodiment will now be described through referenceto FIGS. 1 and 2.

Hydrogen-Containing Gas Manufacturing Apparatus

This hydrogen-containing gas manufacturing apparatus 1 is constituted soas to handle the desulfurization, steam addition, oxygen mixing, andreforming steps to which the hydrocarbon fuel f described above issubjected.

The desulfurization is carried out in a desulfurization chamber 6,producing the feed gas f1 in which the steam s is mixed with thehydrocarbon fuel f sent from the desulfurization chamber 6. FIG. 2 showsthe specific configuration of a feed gas chamber 7, mixing chamber 8,antechamber 9, and catalytic reaction chamber 5 in this apparatus 1. Thepresent invention is characterized by the configuration and usage modeof the antechamber 9, so FIG. 2 only shows the top side of the catalyticreaction chamber 5. The exit side of the catalytic reaction chamber 5provided on the lower side is connected to a hydrogen introduction port2 a of the FT synthesis reactor 2 by a connector pipe 5 c via an outlet5 b.

Desulfurization

A desulfurization catalyst c2, such as a copper-zinc-based high-orderdesulfurization catalyst obtained by mixing a hydrogenationdesulfurization catalyst (such as NiMox or CoMox), an adsorptiondesulfurization agent (ZnO), and copper oxide, zinc oxide, or the like,is disposed in the desulfurization chamber 6, and the sulfur compoundconcentration is lowered to 1 ppb or less in this chamber 6.

In addition to the above-mentioned copper-zinc-based high-orderdesulfurization catalyst, it is also possible to employ a silver-basedcatalyst, as well as a desulfurization catalyst containing nickel,chromium, manganese, iron, cobalt, palladium, iridium, platinum,ruthenium, rhodium, gold, or the like.

Steam Mixing

After undergoing desulfurization, the steam s supplied through aseparate steam supply pipe 10 has added to the hydrocarbon fuel f Theamount of steam s versus the hydrocarbon fuel f here is 0.1 to 3.0 (andpreferably 0.1 to 1.0) as the proportion of H₂O to carbon C contained inthe fuel (the molar ratio H₂O/C). The temperature at this site is about200 to 400° C. (and preferably 200 to 300° C.). In this application, thegas obtained in this manner is called the feed gas f1.

As shown in FIGS. 1 and 2, oxygen o is also supplied to thehydrogen-containing gas manufacturing apparatus 1 of the presentinvention. The feed gas f1 may also be supplied, or the hydrocarbon fuelf and steam s that are the component gases thereof, or a purging gas p(such as an inert gas). These gases are then suitably reacted in areforming unit 11, which will be discussed in detail below.

Reforming Unit 11

As shown in FIG. 2, the reforming unit 11 is equipped with the feed gaschamber 7, the mixing chamber 8, and the antechamber 9 on the upper sideof the unit, and with the catalytic reaction chamber 5 on the lowerside. The upper side of the reforming unit 11 has a sort ofdouble-cylinder structure, allowing the purging gas p to be suppliedthrough the inner pipe 11 a to the lower part of the antechamber 9. Asshown in FIG. 2, a thermocouple t1 for temperature measurement isdisposed inside this inner pipe 11 a, extending to the approximatemiddle of the antechamber. This allows the typical temperature (inlettemperature) of the antechamber 9 to be measured.

Feed Gas Chamber 7

As shown in FIG. 2, the feed gas chamber 7 comprises an introductionport 7 a through which is introduced the feed gas f1 mixed with thesteam s, a middle path section 7 b into which the introduction port 7 aopens, and an expanded channel section 7 c whose channel cross sectionis larger than that of the middle path section 7 b. The mixing chamber 8is provided below this expanded channel section 7 c.

Mixing Chamber 8

The mixing chamber 8 employs what is known as a shell-and-tube type ofmixing structure, and is configured so that oxygen o flows from anoxygen chamber 8 b provided on the outside, into the channel in tubes 8a into which the feed gas f1 flows from the expanded channel section 7c. Therefore, the mixed gas f2 that is a mixture of the feed gas f1 andthe oxygen o can be formed when the oxygen o flows into the feed gas f1.

As shown in FIG. 2, the tubes 8 a extend downward beyond the distancebetween dividers 8 c that partition the mixing chamber 8, and areconstituted so that a sufficiently mixed state is obtained when the gasflows down through this channel.

The amount of oxygen o here with respect to the hydrocarbon fuel f is0.05 to 1.0 (and preferably 0.3 to 0.7) as the proportion of oxygen O₂to carbon C contained in the fuel (the molar ratio O₂/C). Thetemperature at this site is about 200 to 400° C. (and preferably 200 to300° C.). In this application, the gas obtained in this manner is calledthe mixed gas f2.

Antechamber 9

The antechamber 9 is provided so as to function as an adjusting chamberwith respect to the catalytic reaction chamber 5, and comprises anintroduction section 9 a through which the above-mentioned tubes 8 aextend, and an adjustment section 9 b provided in between theintroduction section 9 a and the catalytic reaction chamber 5.

As shown in FIG. 2, the tubes 8 a protrude and extend downward throughthe introduction section 9 a, and the mixed gas f2 is released from thedistal ends of these tubes 8 a. The portion 9 c around the outerperiphery of the tubes 8 a is solid, so no gas accumulates there.Furthermore, a structure is employed in which the above-mentionedpurging gas p is supplied via the inner pipe 11 a to the distal end ofthe introduction section 9 a, and the above-mentioned supply of thepurging gas p and the solid structure of the outside of the tubes 8 acombine to prevent the mixed gas f2 from rising or stagnating.

The adjustment section 9 b suitably adjusts the temperature of theantechamber 9 at this site, its channel expands while the mixed gas f2that has flowed through the tubes 8 a (which are a relatively narrowchannel) is further mixed, and affords smoother introduction into thecatalytic reaction chamber 5. Therefore, as shown in FIG. 2, there is aslight increase in cross sectional area at a gas channel 9 d throughwhich the mixed gas f2 flows in the adjustment section 9 b, and thislowers the flow rate of the gas.

With the configuration described so far, a structure is employed inwhich the channel cross sectional area is set so that the flow rate ofthe mixed gas f2 in the mixing chamber 8 and the antechamber 9 is higherthan the minimum flow rate of the feed gas f1 in the feed gas chamber 7,and the residence time of the mixed gas f2 in this chamber is kept asshort as possible.

As shown in FIG. 2, blocks 9 e and 9 f are provided on the upper andlower sides, respectively, of the adjustment section 9 b in a state offorming the gas channel 9 d of the adjustment section 9 b. The reasonfor using these materials is to prevent heat from the catalytic reactionchamber 5 from propagating upstream, and thereby provide good thermalinsulation. Therefore, these blocks are preferably made of alumina,silicon nitride, or another such ceramic material. In FIG. 2, a ceramicrope 9 g is disposed around the outer periphery of the block 9 f, andkeeps gas from flowing through gaps between the block 9 f and thefire-resistant material.

In the example shown in FIG. 2, a thermal insulating material 9 h thatis breathable is disposed within the gas channel 9 d of the adjustmentsection 9 b, which provides thermal insulation at the boundary betweenthe catalytic reaction chamber 5 and the antechamber 9 and also preventsback-flow of the mixed and unreacted gas.

Catalytic Reaction Chamber 5

The catalytic reaction chamber 5 is the most important part of thehydrogen-containing gas manufacturing apparatus 1 according to thepresent invention, and is where the reforming catalyst c1 is disposed asdiscussed above.

Furthermore, the catalytic reaction chamber 5 according to the presentinvention employs a unique constitution with regard to the distributionand selection of the type of reforming catalyst disposed in itsinterior. This distribution state will be described through reference toFIG. 3.

FIG. 3 shows a graph, with the direction of flow of gas (the mixed gasflows from left to right) on the horizontal axis, and the temperatureand oxygen concentration on the vertical axis. This graph at the top ofFIG. 3 indicates the temperature of the mixed gas with a solid line,based on the temperature axis on the left side, and also indicates theminimum partial-oxidation temperature T1, minimum steam reformingtemperature T2, the self-ignition temperature T3, and the dew pointtemperature T4 with broken lines in the lateral direction.

Meanwhile, in this graph at the top of FIG. 3, the oxygen concentrationis indicated with a one-dot chain line, based on the oxygenconcentration axis on the right side. As is clear from this graph, theoxygen concentration is obtained in the mixing chamber inside theantechamber, the inlet concentration reached at the antechamber inlet ismaintained while the gas reaches the catalytic reaction chamber inlet 5a, and after the gas passes the inlet to the second catalyst section c1b, substantially the entire amount has been consumed.

As shown in FIG. 3, the catalytic reaction chamber 5 comprises, from theinlet 5 a side, a first catalyst section 50 in which is disposed thefirst reforming catalyst c1 a, which has good low-temperature oxidationactivity, and a second catalyst section 51 which is linked on thedownstream side of the first catalyst section 50 and in which isdisposed the second reforming catalyst c1 b, which has good reformingactivity. As described above and as shown in FIG. 3, the first reformingcatalyst c1 a is a ruthenium-based catalyst, a platinum-based catalyst,or a mixed catalyst of these. Meanwhile, the second reforming catalystc1 b is a nickel-based catalyst, a rhodium-based catalyst, or a mixedcatalyst of these.

The supported percentages of the first reforming catalyst c1 a and thesecond reforming catalyst c1 b in this example are 3 wt % ruthenium forthe first catalyst and 3 wt % nickel for the second catalyst.

The distribution in the direction of flow of the first catalyst section50 and the second catalyst section 51 will now be described. Thepositional relationship is determined such that the temperature at theboundary B between the first catalyst section 50 and the second catalystsection 51 is no higher than the self-ignition temperature and is atleast the temperature at which the second catalyst can bring about anoxidation reaction.

The total gas flow supplied to the catalytic reaction chamber 5 is suchthat the gas spatial velocity (calculated for a standard state) perhour, using the amount of first catalyst+second catalyst as a reference,is 750 to 300,000 h⁻¹, and preferably 10,000 to 300,000 h⁻¹, and morepreferably 50,000 to 300,000 h⁻¹.

There are no particular restrictions on the pressure during thereactions, and the reaction pressure can be varied according to theapplication. When the present invention is used in applications for GTLor other such liquid fuel synthesis, a pressure of about 2 to 7 MPa isused. When it is used in applications for the manufacture of hydrogenfor fuel cells, on the other hand, the pressure is usually close tonormal pressure (such as 1 MPa or lower).

The above is the constitution on the hardware side of thehydrogen-containing gas manufacturing apparatus 1 according to thepresent invention, but the apparatus of the present invention isconfigured so as to achieve the proper reaction state in the antechamber9 and the catalytic reaction chamber 5.

Specifically, the apparatus 1 of the present invention is designed so asto achieve the proper inlet temperature of the mixed gas f2 going intothe catalytic reaction chamber 5. For instance, in the constitutiondescribed so far, the gas channel 9 d of the mixed gas f2 is maderelatively small, and the flow rate in this gas channel 9 d is raised,which keeps the residence time of the mixed gas f2 inside theantechamber 9 to a specific time or less. Also, good thermal insulationis achieved at the boundary between the catalytic reaction chamber 5 andthe antechamber 9, so that the temperature of the catalytic reactionchamber 5 does not affect the antechamber 9. Introducing a purging gas pinto the antechamber 9 and preventing stagnation and back-flow of themixed gas f2, for example, are another feature on the hardware side inthe present invention.

As shown in FIG. 1, the hydrogen-containing gas manufacturing apparatus1 of the present invention is equipped with a control device 13 forcontrolling the reaction state. The apparatus is configured so that thetype, amount, and temperature of the hydrocarbon fuel f going into thesystem, the amount and temperature of the steam s going into the system,and the amount and temperature of the oxygen o going into the system canbe monitored by the control device 13.

Meanwhile, as shown in FIG. 2, the apparatus is configured so that thetemperature at the inlet and outlet of the adjustment section 9 b of theantechamber 9 (the inlet 5 a of the catalytic reaction chamber), and thetemperature in the flow direction within the catalytic reaction chamber5 can be monitored by the thermocouples t1 and t2 inserted into thereforming unit 11 from the upper and lower sides of the unit 11described above.

The amount of hydrocarbon fuel, the amount of steam, and the amount ofoxygen going into the hydrogen-containing gas manufacturing apparatus 1can be adjusted according to control commands from the control device13.

The configuration of the control device 13 will now be described throughreference to FIGS. 1 and 3. This control device 13 comprises atemperature setting means 13 a for setting the temperature of the mixingchamber 8 and the antechamber 9 to a temperature below the self-ignitiontemperature T3, where the self-ignition temperature is the temperatureat which the mixed gas f2 self-ignites during the advection periodrequired for the mixed gas f2 to move from the mixing chamber 8 to thecatalytic reaction chamber 5, at a temperature that is at least theminimum partial-oxidation temperature T1 and is below the minimum steamreforming temperature T2, where the minimum partial-oxidationtemperature T1 is the minimum temperature at which the first reformingcatalyst c1 a undergoes the partial oxidation reaction, and the minimumsteam reforming temperature T2 is the minimum temperature at which thesecond reforming catalyst c1 b undergoes the steam reforming reaction.

This temperature setting means 13 a comprises an antechamber mixed gastemperature maintenance means (simply labeled “temperature maintenancemeans” in FIG. 1) 13 b for maintaining the temperature of the mixed gasf2 flowing through the antechamber 9 at a temperature that is lower thana maximum antechamber temperature and higher than a minimum antechambertemperature, where the minimum antechamber temperature is thetemperature that is higher between the minimum partial-oxidationtemperature and the dew point temperature T4 of the mixed gas f2, andthe maximum antechamber temperature is the self-ignition temperature ofthe mixed gas f2.

The minimum and maximum temperatures in the control device 13 will nowbe described.

Minimum Temperature

The minimum partial-oxidation temperature is the minimum temperature T1at which the mixed gas f2 undergoes a partial oxidation reaction uponcontact with the first reforming catalyst c1 a, and this minimumtemperature T1 is determined by the first reforming catalyst c1 a heldin the catalytic reaction chamber 5. For example, if the first reformingcatalyst c1 a is the above-mentioned ruthenium-based catalyst, thistemperature is about 200° C., and if the first reforming catalyst c1 ais a platinum-based catalyst, the temperature is again about 200° C.Therefore, this minimum partial-oxidation temperature is stored in astorage means 13 c provided to the control device 13, so that theminimum partial-oxidation temperature T1 can be read out and utilized asneeded on the control device 13 side.

As to the mixed gas f2, meanwhile, the dew point temperature T4 of themixed gas is determined according to the amounts of the hydrocarbon fuelf, steam s, and oxygen o. In view of this, dew point temperature datacorresponding to the amounts of gas used is stored in the storage means13 c, and this data can be used to estimate the current dew pointtemperature T4 of the mixed gas f2 present in the antechamber 9 from theamounts of the gases.

Therefore, the minimum temperature (the minimum antechamber temperature)is found as the temperature that is higher between the minimumpartial-oxidation temperature T1 based on the type of first reformingcatalyst c1 a, and the dew point temperature T4 of the mixed gas f2estimated from the composition of the mixed gas f2 presumed to bepresent in the antechamber.

Maximum Temperature

The self-ignition temperature T3 of the mixed gas f2 present in theantechamber 9 depends on the composition of the mixed gas f2 in theantechamber 9 and on its residence time in the antechamber 9 (this“residence time” is the time from when the gas exits the mixing chamber8 until it reaches the inlet 5 a of the catalytic reaction chamber 5,after the mixing of the oxygen o in the mixing chamber 8, and in thepresent application, this refers to the advection time required for themixed gas f2 to move through the tubes on the exit side of the mixingchamber 8 up to the inlet 5 a of the catalytic reaction chamber 5).

In view of this, the self-ignition temperature T3 corresponding to thecompositional state of the mixed gas f2 first ignited during theresidence time is stored in the storage means 13 c, and the maximumtemperature can be obtained at this temperature. This relationshipbetween the residence time (labeled “ignition lag time” in the FIG. 4)and the self-ignition temperature T3 (labeled “mixed gas temperature” inFIG. 4) is shown in FIG. 4 for the mixed gas f2. This graph shows a casein which the mixed gas f2 contains a hydrocarbon fuel that is naturalgas, and in which N₂/C is 0.6 to 1.0 and O₂/C is 0.1 or 0.4. Thepressure of the mixed gas in this state is 4 MPa. The combustionreaction is rate-determined by the frequency of collisions in the mixedgas, and the actual frequency factors depend on the molecular diameterand degree of freedom, but if we let the collision frequency of H₂O be1, then that of N₂ is about 0.7 to 0.8, and in the example shown in FIG.4, nitrogen gas is introduced instead of steam.

With the control device 13, the temperature setting means 13 a, and morespecifically, the antechamber mixed gas temperature maintenance means 13b, ensures a good operating state by adjusting the amount of hydrocarbonfuel added, the amount of steam added, the amount of oxygen added, andso forth according to the procedure described above.

The operating state of the hydrogen-containing gas manufacturingapparatus 1 according to the present invention controlled by the controldevice 13 will now be described.

1. When the mixed gas temperature inside the antechamber 9 is within themaximum antechamber temperature (self-ignition temperature) and theminimum antechamber temperature (the temperature that is higher betweenthe minimum partial-oxidation temperature and the dew point temperature)

In this case, the reaction in the catalytic reaction chamber 5 ispresumed to be in a fairly proper state. However, even in a proper statesuch as this, the state of the catalytic reaction chamber 5 is keptstable, so the temperature of the mixed gas f2 in the antechamber 9 iscontrolled according to the temperature of the catalytic reactionchamber 5, within the range of the maximum antechamber temperature andminimum antechamber temperature.

Here, if a temperature elevation operation is necessary, this can beaccomplished by either increasing the amount of oxygen with the amountof hydrocarbon kept constant, or reducing the amount of steam.Conversely, if a temperature reduction operation is necessary, this canbe accomplished by either reducing the amount of oxygen or increasingthe amount of steam.

The following is an operating example of this embodiment. In thisexample, ruthenium (supported percentage of 0.7 wt %) was used as thefirst catalyst, and nickel (supported percentage of 10 wt %) was used asthe second catalyst.

Operating Conditions

-   -   Feed gas f1        -   Composition: 88.4% methane, 7.3% ethane, 3.1% propane, 0.6%            n-butane, 0.6% i-butane        -   Added amount: 678 Nm³/hr    -   Steam        -   Added amount: 378 Nm³/hr    -   Oxygen        -   Added amount: 157 Nm³/hr        -   (H₂O/C=0.6, O₂/C=0.2)    -   Antechamber inlet temperature: higher than 200° C., lower than        300° C.    -   Self-ignition temperature of mixed gas: 300 to 350° C.    -   Antechamber residence time of mixed gas: 0.48 sec    -   Dew point of mixed gas: 196° C.    -   Catalytic reaction chamber inlet temperature: higher than 200°        C., lower than 300° C.    -   Reaction pressure: 4 MPaG    -   SV=40,000 h⁻¹    -   Catalytic reaction chamber volume: 33 dm³ (liters)    -   Minimum partial-oxidation temperature of first catalyst: 200° C.    -   Minimum partial-oxidation temperature of second catalyst: 250°        C.

Under these conditions, reforming could be performed such that theproportion of hydroacid H₂ to carbon CO contained in the produced gas atthe catalytic reaction chamber outlet 5 c, as the molar ratio H₂/CO, wasH₂/CO=2.

Variations on the First Embodiment

(1) In the above embodiment, a gas channel of substantially the samediameter as the tubes extending from the mixing chamber was provided inthe adjusting section of the antechamber, the flow rate of the mixed gaswas kept relatively high by means of the tubes and the gas channel, sothat the residence time was shorter as the mixed gas was introduced intothe catalytic reaction chamber, but as shown in FIG. 5, a mergingchannel 90 may be provided downstream from the outlet of the tubes, sothat the mixed gas f2 flows into the catalytic reaction chamber 5 viathis merging channel 90. However, the cross sectional area of thismerging channel 90 shall afford a flow rate such that the gas can reachthe catalyst layer in a residence time at that site that is less thanthe self-ignition lag time. When this is done, the mixed gas f2 has moreuniform properties, and the mixed gas f2 will spread out well in thedirection of the catalytic reaction chamber cross section near the inletto the catalytic reaction chamber 5.

(2) In the above embodiment, the temperature setting means 13 a and thetemperature maintenance means 13 b were provided to thehydrogen-containing gas manufacturing apparatus, and the amounts ofsteam and oxygen with respect to the hydrocarbon fuel were proactivelycontrolled to maintain the reaction in the catalyst reaction section inthe proper state, but if a normal operating can be substantiallymaintained anyway, since the flow rates in the chambers 7, 8, and 9 aresubstantially determined in the reforming unit 11 described above, thechannel cross sectional structure may be such that the mixed gas willhave the proper temperature in the antechamber 9.

Specifically, the minimum partial-oxidation temperature is determined bythe reforming catalyst c1, and if the composition of the mixed gas f2 isdetermined, then the dew point thereof is also determined, and theminimum antechamber temperature referred to in this application isdetermined.

Meanwhile, as to the maximum antechamber temperature, the maximumresidence time of the mixed gas f2 from the mixing chamber 8 until thecatalytic reaction chamber 5 is reached is determined by the shape ofthe inside of the tubes 8 a through which the gas flows, and that of thegas channel 9 d of the adjustment section 9 b downstream from the tubes8 a. In view of this, the relationship between the mixed gas temperatureand its residence time as described above and shown in FIG. 4 is foundahead of time, and the maximum antechamber temperature is set to be thetemperature at which the mixed gas f2 does not self-ignite even when themixed gas f2 has been in the antechamber for the above-mentioned maximumresidence time, so that the object of the present invention can beachieved.

(3) In the above embodiment, an example was given in which thetemperature of the mixed gas in the antechamber was controlled accordingto the typical temperature of the catalytic reaction chamber, butbasically what is important is that a partial oxidation reaction canoccur at the inlet to the catalytic reaction chamber, so the control ofthe temperature setting means 13 a and the temperature maintenance means13 b described above can be constituted so that the temperature of themixed gas in the antechamber is guided toward the minimum antechambertemperature.

This ensures that the partial oxidation reaction required for reformingwill occur.

(4) In the above embodiment, an example was given in which reforming wasperformed by setting the residence time of the mixed gas in theantechamber, and setting the temperature of the antechamber to atemperature at which the mixed gas would not self-ignite when the mixedgas had been in the antechamber for that residence time, but a means maybe provided for proactively preventing the propagation of flame withinthe antechamber.

FIG. 6 shows an example of this, in which a flame arrestor 60 isdisposed at the distal end of the tubes 8 a, and the inner walls 61 ofthe gas channel 9 d and the sites 62 where stagnation occurs aresubjected to a gold coating treatment w to prevent flame propagation.This is another way to prevent flame formation and propagation in theantechamber 9.

Second Embodiment

FIG. 7 illustrates the overall structure of the hydrogen-containing gasmanufacturing apparatus 1 of this embodiment, FIGS. 8 and 9 are diagramscorresponding to FIG. 2 of the first embodiment given above, and FIG. 10is a diagram corresponding to FIG. 3.

As can be seen from FIG. 7, no purging gas p is used in the reformingunit 5 in this example. On the other hand, the steps of desulfurization,steam addition, oxygen mixing, and reforming of the hydrocarbon fuel fas described in the first embodiment remain basically unchanged.

The above-mentioned desulfurization is carried out in thedesulfurization chamber 6, and involves lowering the sulfur compoundconcentration to 1 ppb or less. The steam s is mixed with thehydrocarbon fuel f sent out of the desulfurization chamber 6 to producethe feed gas f1. The amount of steam s with respect to the hydrocarbonfuel f is such that the proportion of steam H₂O to carbon C contained inthe fuel (the molar ratio H₂O/C) is 0.1 to 3.0 (and preferably 0.1 to1.0). The temperature at this site is about 200 to 400° C. (andpreferably 200 to 300° C.).

FIGS. 8 and 9 show the specific structure of the feed gas chamber 7, themixing chamber 8, the antechamber 9, and the catalytic reaction chamber5 of this apparatus 1. This embodiment is characterized by theconfiguration of the antechamber 9 and the catalytic reaction chamber 5and by how these are used, so the drawings only show the upper side ofthe catalytic reaction chamber 5. The exit side provided on the lowerside of the catalytic reaction chamber 5 is connected by the connectorpipe 5 c and via an outlet 5 b to the hydrogen introduction port 2 a ofthe FT synthesis reactor 2.

As shown in FIG. 8, the reforming unit 110 in this example has asingle-nozzle structure that generates no circulating flow, a baffle 111is provided to a premixing zone, and the oxygen o and feed gas f1 can bequickly and uniformly mixed.

Reforming Unit 110

As shown in FIG. 9, the reforming unit 110 comprises the feed gaschamber 7, the mixing chamber 8, and the antechamber 9 on the upper sideof the unit, and the catalytic reaction chamber 5 is provided on thelower side. The upper side of the reforming unit 110 has a sort ofdouble-cylinder structure, allowing the oxygen o to be supplied throughthe inner pipe 110 a to the mixing chamber 8 and the antechamber 9. Asshown in FIG. 9, thermocouples t1 and t2 for temperature measurement aredisposed at the lower part of the inner pipe 110 a and the lower part ofthe feed gas chamber 7, respectively, allows the typical temperature(inlet temperature) of the inner pipe and the antechamber 9 to bemeasured. The typical temperature measured by these thermocouples t1 andt2 is used during temperature setting and maintenance by the controldevice 13.

Feed Gas Chamber 7

As shown in FIG. 8, the feed gas chamber 7 comprises an introductionport 7 a through which is introduced the feed gas f1 mixed with thesteam s, a middle path section 7 b into which the introduction port 7 aopens, and an expanded channel section 7 c whose channel cross sectionis larger than that of the middle path section 7 b. The mixing chamber 8is provided below this expanded channel section 7 c.

Mixing Chamber 8

As shown in FIG. 9, the mixing chamber 8 employs what is known as asingle-nozzle baffle type of mixing structure, and is configured so thatoxygen o coming through the inner pipe 110 a and the feed gas f1 fromthe expanded channel section 7 c hit baffle-style collision plates 80and 81 provided in the mixing chamber 8, forming a mixed gas f2 that isuniformly mixed. As shown in FIG. 9, the collision plates 80 and 81 areprovided a specific distance apart, and the mixed gas f2 repeatedlycollides with these and spreads out, resulting in the desired uniformstate of mixing. A pair of upper and lower collision plates 80 thatsandwich the collision plate 81 in the middle each have a plurality offlow-through holes 80 a (eight are shown in the drawing) around theouter periphery, as shown on the right side in FIG. 9. The collisionplate 81 disposed in the middle has a flow-through hole 81 a in itscenter.

Here, the amount of oxygen o with respect to the hydrocarbon fuel f is0.05 to 1.0 (and preferably 0.3 to 0.7) as the proportion of oxygen O₂to carbon C contained in the fuel (the molar ratio O₂/C). Thetemperature at this site is about 200 to 400° C. (and preferably 200 to300° C.). In this application, the gas obtained in this manner is calledthe mixed gas f2.

Antechamber 9

The antechamber 9 is provided so as to function as an adjusting chamberwith respect to the catalytic reaction chamber 5, and comprises anintroduction section 9 a equipped with an alumina ball layer 9 c forfurther mixing and adjusting the mixed gas f2 supplied from the mixingchamber 8 as described above, and an adjustment section 9 b equippedwith a block 9 e.

The introduction section 9 a suitably adjusts the temperature of theantechamber 9 at this site, further mixes the mixed gas f2 flowing infrom the mixing chamber 8 while first expanding the channel, andsmoothly introduces the mixed gas f2 in the form of a ring into thecatalytic reaction chamber 5. Therefore, as shown in the drawing, thechannel of the mixed gas f2 expands in the adjustment section 9 b, andthe gas flow rate decreases.

As shown in FIG. 9, the result of providing the block 9 e to theadjustment section 9 b is that the flow into the catalytic reactionchamber 5 becomes a flow in the form of a double cylinder consisting ofan inner flow FI and an outer flow FO as it is introduced into thecatalytic reaction chamber 5.

With the constitution described up to this point, the channel crosssectional area is set so that the flow rate of the mixed gas f2 in themixing chamber 8 and the antechamber 9 is higher than the minimum flowrate of the feed gas f1 in the feed gas chamber 7, and the residencetime of the mixed gas f2 in this chamber is kept as short as possible.

The role of the block 9 e described above is to determine the flow, andit is also intended to prevent heat from the catalytic reaction chamber5 from propagating upstream, and thereby provide good thermalinsulation. Therefore, this block is preferably made of alumina, siliconnitride, or another such ceramic material. In FIG. 9, small-diameteralumina balls are disposed around the outer periphery of the block 9 eto prevent the gas flow rate from decreasing in the gap between theblock 9 f and the fire-resistant material.

Furthermore, in the example shown in the drawings, alumina balls arealso disposed in the gas channel 9 d of the adjustment section 9 b,which provides thermal insulation at the boundary between the catalyticreaction chamber 5 and the antechamber 9 and also prevents back-flow ofthe mixed and unreacted gas.

Catalytic Reaction Chamber 5

The catalytic reaction chamber 5 is the most important part of thehydrogen-containing gas manufacturing apparatus 1 according to thepresent invention, and is where the reforming catalyst d1 is disposed.Again in this example, the catalytic reaction chamber 5 employs a uniqueconstitution with regard to the distribution and selection of the typeof reforming catalyst disposed in its interior. This distribution statewill be described through reference to FIG. 10.

FIG. 10 shows a graph, with the direction of flow of gas (the mixed gasflows from left to right) on the horizontal axis, and the temperature onthe vertical axis. This graph at the top of FIG. 10 indicates thetemperature of the mixed gas with a solid line, based on the temperatureaxis on the left side, and also indicates the minimum partial-oxidationtemperature T1, minimum steam reforming temperature T2, theself-ignition temperature T3, and the dew point temperature T4 withbroken lines in the lateral direction.

As shown in FIG. 10, the catalytic reaction chamber 5 comprises, fromthe inlet 5 a side, a first catalyst section 50 in which is disposed ata low concentration a third reforming catalyst d1, which has goodlow-temperature oxidation activity and also has good reforming activity,a heat blocking layer 55 which is provided on the downstream side of thefirst catalyst section 50 and in which alumina balls are disposed, and asecond catalyst section 51 in which the third reforming catalyst d1 isdisposed at a higher concentration than in the first catalyst section50. The third reforming catalyst d1 here is a ruthenium-based catalystas shown in FIG. 10. In the following description, the catalyst disposedat a low concentration in the first catalyst section 50 will be calledthe “first reforming catalyst,” while the catalyst disposed at a higherconcentration in the second catalyst section 51 will be called the“second reforming catalyst.”

The supported percentage of the first reforming catalyst is 0.014 wt %,and the supported percentage of the second reforming catalyst is 0.7 to3 wt %. The catalyst concentration (amount of catalyst per unit ofvolume) of the first catalyst section 50 is lower than that of thesecond catalyst section 51.

The distribution in the direction of flow of the first catalyst section50 and the second catalyst section 51 will now be described further. Ina normal operating state, the positional (position in the flowdirection) relationship is determined so that the temperature at thefirst catalyst section outlet 50 o will be no higher than theself-ignition temperature and at least the temperature at which thesecond catalyst begins partial oxidation.

The total gas flow supplied to the catalytic reaction chamber 5 is suchthat the gas spatial velocity (calculated for a standard state) perhour, using the amount of first catalyst+second catalyst as a reference,is 750 to 300,000 h⁻¹, and preferably 10,000 to 300,000 h⁻¹, and morepreferably 50,000 to 300,000 h⁻¹.

There are no particular restrictions on the pressure during thereactions, and the reaction pressure can be varied according to theapplication. When [the present invention] is used in applications forGTL or other such liquid fuel synthesis, a pressure of about 2 to 7 MPais used. When it is used in applications for the manufacture of hydrogenfor fuel cells, on the other hand, the pressure is usually close tonormal pressure (such as 1 MPa or lower).

As will be described below, the effect of employing a catalytic reactionchamber with a structure such as this is that the temperature can besteadily raised while the partial oxidation reaction is being conductedin the first catalyst section 50, and the first catalyst section outlettemperature T50 o can be controlled to no higher than the self-ignitiontemperature and at least the temperature at which partial oxidationbegins in the second catalyst section 51.

Meanwhile, with the second catalyst section 51, partial oxidation beginsnear the inlet, the temperature rises a specific amount and reaches thetemperature at which the steam reforming reaction will substantiallyproceed near this inlet, and then reaches the peak temperature.

Specifically, the temperature distribution near the first catalystsection outlet 50 o and the second catalyst section inlet 51 i (near thedownstream side of the flow) is such that the temperature is higher asthe gas moves farther downstream, as shown in FIG. 10. However, thepresence of the heat blocking layer provided between the first catalystsection 50 and the second catalyst section 51 limits heat transfer fromthe second catalyst section inlet 51 i side to the first catalystsection outlet 50 o side, and merely by providing the heat blockinglayer 55 that is a thin layer in the flow direction, the temperature ofthe first catalyst section 50 can be maintained at or below theself-ignition temperature, and partial oxidation by the catalyst at thesecond catalyst section inlet 51 i and, in turn, steam reforming can becarried out effectively.

Catalytic Reaction Chamber

Experiment Related to Second Embodiment

The results of simulation experiments conducted by the inventors willnow be described through reference to FIGS. 11 and 12.

In these simulation experiments, the inventors readied experimentalequipment that simulated the catalytic reaction chamber 5 equipped withthe first catalyst section 50, the heat blocking layer 55, and thesecond catalyst section 51 of the second embodiment given above, as wellas experimental equipment equipped with no heat blocking layer 55, andwith the second catalyst section 51 provided on the downstream side ofthe first catalyst section 50. In FIGS. 11 and 12, the horizontal axisis the distance from the catalytic reaction chamber inlet, and thevertical axis is the temperature. In these graphs, the first catalystsection 50, the heat blocking layer 55, and the second catalyst section51 are differentiated schematically beneath each graph.

The conditions of these experiments are summarized below in outlineform.

-   -   Feed gas f1        -   Composition: 88.5% methane, 7.2% ethane, 3.1% propane, 0.6%            n-butane, 0.6% i-butane        -   Added amount: 16.03 dm³ (liters)/min    -   Steam        -   Added amount: 1154 dm³ (liters)/min    -   Oxygen        -   Added amount: 3.85 dm³ (liters)/min        -   (H₂O/C=0.6, O₂/C=0.2)    -   Antechamber inlet temperature: higher than 200° C., lower than        300° C.    -   Self-ignition temperature of mixed gas: 300 to 350° C.    -   Dew point of mixed gas: 122° C.    -   Catalytic reaction chamber inlet temperature: higher than 200°        C., lower than 300° C.    -   Reaction pressure: 0.5 to 0.52 MPa (5.1 to 5.3 kg/cm³)    -   SV (first catalyst section)=20,000 h⁻¹    -   First catalytic reaction chamber volume: 0.1 dm³ (liters)    -   SV (second catalyst section)=100,000 h⁻¹    -   Second catalytic reaction chamber volume: 0.02 dm³ (liters)    -   Minimum partial-oxidation temperature of first catalyst: 200° C.    -   Minimum partial-oxidation temperature of second catalyst: 200°        C.

The apparatus was operated under these conditions with the supportedpercentage of the first catalyst at 0.014 wt % and the supportedpercentage of the second catalyst at 0.7 wt %, whereupon the amount ofhydrogen, which was substantially 0 wt % at the catalytic reactionchamber inlet, could be raised to 40 wt % at the reaction chamber outletby the reforming reaction.

Catalyst Concentration of First Catalyst Component 50

FIG. 11 shows the temperature distribution when the same catalyticreaction chamber structure as in the second embodiment was employed, andwhen the supported percentage of the first reforming catalyst wasvaried.

In FIG. 11, different supported percentages of the first reformingcatalyst disposed in the first catalyst section 50 were used, and thedifferences are shown to the right of the graph.

The supported percentage of the ruthenium catalyst (as the supportedpercentage of the first reforming catalyst) was varied between 0.007 wt%, 0.014 wt %, and 0.035 wt %. Alumina balls were provided for the heatblocking layer 55, and the supported percentage of the rutheniumcatalyst at the second catalyst section was 0.7 wt %. In this example,material with the above-mentioned supported percentages was placed at100% of the site.

As is clear from FIG. 11, in the two examples in which the concentration(supported percentage) of catalyst in the first catalyst section was onthe lower side, a low-temperature state at or below the self-ignitiontemperature was maintained up to the first catalyst section outlet 50 o,the temperature rose sharply near the second catalyst section inlet 51i, and the peak temperature appeared near the downstream side of thesecond catalyst section inlet 51 i. Therefore, the temperaturedistribution that is the goal with the present invention can befavorably attained.

Further, the result on the higher concentration side was such that thetemperature of the first catalyst section outlet 50 o was higher withrespect to the result on the lower concentration side, and it can beseen that the partial oxidation reaction produced by the first catalystsection 50 can be utilized favorably by suitably selecting the catalystconcentration. The reaction gas composition was examined when theruthenium concentration was set at 0.014 wt %, and was also examined onthe side 10 cm in from the first catalyst section inlet 50 i, whichrevealed that the H₂ and CO₂ concentrations had increased at thisposition, while the O₂ and CH₄ concentration had decreased. Thus, thisslight increase in temperature seems to have a significant effect.

As a result, it can be seen that suitable selection of the catalystconcentration allows the partial oxidation reaction generated in thefirst catalyst section 50 to be utilized favorably.

Meanwhile, the example with the highest concentration is one in whichthe peak temperature occurs near the inlet to the first catalystsection, and this is undesirable.

The inventors also conducted experiments in which alumina balls havingno catalytic activity were disposed in the first catalyst section 50,but the result was close to that when the ruthenium concentration was0.007 wt %. As a result, it is presumed that when the concentration ofthe catalyst disposed in the first catalyst section is decreased to thislevel, the effect of thermal conduction will be more apparent.

Heat Blocking Layer 55

The above-mentioned experiment example illustrated in FIG. 11 is anexample of providing the heat blocking layer 55 between the firstcatalyst section 50 and the second catalyst section 51. FIG. 12, on theother hand, shows the results when the first catalyst section 50 and thesecond catalyst section 51 are linked without the heat blocking layer 55being provided, and a catalyst with a ruthenium concentration of 0.007wt % was disposed in the first catalyst section 50. As is clear from thegraph, the peak temperature occurs near the inlet to the first catalystsection, which is undesirable.

Variations on the Second Embodiment

(1) In the above embodiment, 100% of catalysts with specific, differingsupported percentages were held in the first catalyst section 50 and thesecond catalyst section 51, and the amount (concentration) of catalystat these sites was suitably adjusted. However, for the catalyst to beheld in each catalyst section, an inert member having no catalyticactivity (alumina balls) may be mixed in to adjust the catalystconcentration. Specifically, the catalyst concentration of the firstcatalyst section 50 is set lower than the catalyst concentration of thesecond catalyst section 51, so the catalyst concentration at these sitesmay be set to a suitable state by utilizing catalysts with the samesupported percentage and mixing in a suitable amount of alumina balls orthe like on the first catalyst section 50 side.

(2) In the above embodiment, the heat blocking layer 55 was providedbetween the first catalyst section 50 and the second catalyst section51, but this heat blocking layer 55 does not have to be provided as longas the position of the peak temperature can be kept to the inside nearthe second catalyst section 51, depending on the flow rate of the gasflowing through the catalytic reaction chamber 5.

Variations Common to the First and Second Embodiments

In the embodiments described so far, steam was added to a hydrocarbonfuel, a partial oxidation reaction was conducted, and then a steamreforming reaction was brought about, but what is known as a carbondioxide reforming reaction may instead be brought about. This carbondioxide reforming reaction is also an endothermic reaction, and thereaction proceeds according to Chemical Formula 3 given below.

C_(n)H_(m) +nCO₂→2nCO+m/2H₂ (endothermic reaction)  [Chemical Formula 3]

FIG. 13 corresponds to FIG. 1 and illustrates an example of a GTLmanufacturing process in which steam reforming according to ChemicalFormula 2 and carbon dioxide reforming according to Chemical Formula 3are conducted. The equipment is configured the same as what is shown inFIG. 1, but whereas in the example shown in FIG. 1 the feed gas f1 wasobtained by adding only the steam s to the hydrocarbon fuel f, in thisexample the feed gas f1 is obtained by adding the steam s and carbondioxide (CO₂). With this GTL manufacturing process, a steam reformingreaction and a carbon dioxide reforming reaction can both proceed.

Again with this reaction mode, with the method and apparatus formanufacturing a hydrogen-containing gas according to the presentinvention, the desired good state is obtained in the antechamber and inthe subsequent catalytic reaction chamber.

INDUSTRIAL APPLICABILITY

Given a method for manufacturing a hydrogen-containing gas by means of apartial oxidation reaction and a steam reforming reaction, a stablestate is obtained in an antechamber provided on the upstream side of acatalytic reaction chamber, and a manufacturing apparatus that makes useof this method is also obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the configuration of a GTL manufacturing processequipped with the hydrogen-containing gas manufacturing apparatusaccording to the present invention;

FIG. 2 is a diagram of the configuration of the upper part of areforming unit;

FIG. 3 illustrates the relationship between the temperature at the inletof the catalytic reaction chamber and the temperature inside thecatalytic reaction chamber;

FIG. 4 illustrates the relationship between the mixed gas temperatureand the self-ignition lag time;

FIG. 5 is a diagram of an example of another configuration of theantechamber;

FIG. 6 is a diagram of an example in which a flame propagationsuppression means is provided to the antechamber configurationcorresponding to FIG. 2;

FIG. 7 is a diagram of the configuration of a GTL manufacturing processequipped with the hydrogen-containing gas manufacturing apparatus of asecond embodiment according to the present invention;

FIG. 8 is a simplified diagram of the configuration of the upper part ofthe reforming unit in the second embodiment;

FIG. 9 is a detail diagram of the site of the inlet to the reformingunit in the second embodiment;

FIG. 10 illustrates the relationship between the temperature at theinlet of the catalytic reaction chamber and the temperature inside thecatalytic reaction chamber in the second embodiment;

FIG. 11 is a graph of the temperature distribution and the catalystconcentration in the first catalyst section;

FIG. 12 is a graph of experiment results when no heat blocking layer wasprovided; and

FIG. 13 is a diagram of another embodiment in which carbon dioxidereforming is conducted along with steam reforming.

EXPLANATION OF THE REFERENCE NUMERALS

-   1 hydrogen-containing gas manufacturing apparatus-   2 FT synthesis reactor-   4 desulfurization apparatus-   5 catalytic reaction chamber-   7 mixed gas chamber-   8 mixing chamber-   8 a tube-   8 b oxygen chamber-   9 antechamber-   11 reforming unit-   13 control device-   13 a temperature setting means-   13 b temperature maintenance means-   13 c storage means-   50 first catalyst section-   51 second catalyst section-   c1 reforming catalyst-   c1 a first reforming catalyst-   c1 b second reforming catalyst-   c2 desulfurization catalyst-   f hydrocarbon fuel-   f1 feed gas-   f2 mixed gas-   h hydrogen-rich gas-   o oxygen-   p purging gas-   s steam

1-22. (canceled) 23: A method for manufacturing a hydrogen-containinggas, comprising: a mixing step of mixing, in a mixing chamber, anoxygen-containing gas with a feed gas obtained by mixing steam with ahydrocarbon fuel; and a reformation step of guiding the mixed gasobtained in the mixing chamber into a catalytic reaction chamber via anantechamber provided on the upstream side of the catalytic reactionchamber and bringing the mixed gas into contact with at least onereforming catalyst and thereby obtaining a hydrogen-containing gas bymeans of a partial oxidation reaction and a steam reforming reaction,wherein the catalytic reaction chamber includes a first catalyst sectionin which is disposed a first reforming catalyst that has goodlow-temperature oxidation activity and a second catalyst section whichis provided on the downstream side of the first catalyst section and inwhich is disposed a second reforming catalyst that has good reformingactivity, and the mixed gas is introduced into the catalytic reactionchamber after the temperature of the antechamber has been set to atleast a minimum partial-oxidation temperature and below a self-ignitiontemperature, where the self-ignition temperature is the temperature atwhich the mixed gas self-ignites during the advection period requiredfor the mixed gas to move from the mixing chamber to the catalyticreaction chamber, and the minimum partial-oxidation temperature is theminimum temperature at which the first reforming catalyst undergoes thepartial oxidation reaction. 24: The method for manufacturing ahydrogen-containing gas according to claim 23, wherein the firstreforming catalyst concentration of the first catalyst section is theconcentration at which a first catalyst section outlet temperature is nohigher than the self-ignition temperature and is at least thetemperature at which the second catalyst undergoes partial oxidation ina state in which the temperature of the antechamber has been set to atleast the minimum partial-oxidation temperature and below theself-ignition temperature. 25: The method for manufacturing ahydrogen-containing gas according to claim 24, further comprising a stepof providing a heat blocking layer with lower thermal conductioncharacteristics than the first catalyst section between the firstcatalyst section and the second catalyst section. 26: The method formanufacturing a hydrogen-containing gas according to claim 24, furthercomprising a step of mixing an inert member that has no catalyticactivity with the first catalyst section to set the first reformingcatalyst concentration of the first catalyst section. 27: The method formanufacturing a hydrogen-containing gas according to claim 24, whereinthe first catalyst section outlet temperature is the self-ignitiontemperature. 28: The method for manufacturing a hydrogen-containing gasaccording to claim 27, wherein if the temperature that is higher betweenthe minimum partial-oxidation temperature and the dew point temperatureof the mixed gas is taken as the minimum antechamber temperature, andthe self-ignition temperature is taken as the maximum antechambertemperature, the temperature of the mixed gas flowing through theantechamber is maintained higher than the minimum antechambertemperature and lower than the maximum antechamber temperature. 29: Themethod for manufacturing a hydrogen-containing gas according to claim28, wherein the sulfur compound concentration of the hydrocarbon fuel is1 ppb or less. 30: The method for manufacturing a hydrogen-containinggas according to claim 23, wherein the first reforming catalyst is areforming catalyst that contains at least one of ruthenium and platinum,and the second reforming catalyst is a reforming catalyst that containsat least one of nickel, rhodium, and ruthenium. 31: An apparatus formanufacturing a hydrogen-containing gas, comprising: a mixing chamber inwhich an oxygen-containing gas is mixed with a feed gas obtained bymixing steam with a hydrocarbon fuel; a catalytic reaction chamber intowhich the mixed gas obtained in the mixing chamber is guided via anantechamber and brought into contact with at least one reformingcatalyst and a hydrogen-containing gas is obtained by means of a partialoxidation reaction and a steam reforming reaction, the catalyticreaction chamber comprising, from the inlet side, a first catalystsection in which is disposed a first reforming catalyst that has goodlow-temperature oxidation activity, and a second catalyst section whichis provided on the downstream side of the first catalyst section and inwhich is disposed a second reforming catalyst that has good reformingactivity; and an antechamber temperature setting means for setting thetemperature of the antechamber to at least a minimum partial-oxidationtemperature and below a self-ignition temperature, where theself-ignition temperature is the temperature at which the mixed gasself-ignites during the advection period required for the mixed gas tomove from the mixing chamber to the catalytic reaction chamber, and theminimum partial-oxidation temperature is the minimum temperature atwhich the first reforming catalyst undergoes the partial oxidationreaction. 32: The apparatus for manufacturing a hydrogen-containing gasaccording to claim 31, wherein the first reforming catalystconcentration of the first catalyst section is the concentration atwhich a first catalyst section outlet temperature is no higher than theself-ignition temperature and is at least the temperature at which thesecond catalyst undergoes partial oxidation in a state in which thetemperature of the antechamber has been set to at least the minimumpartial-oxidation temperature and below the self-ignition temperature.33: The apparatus for manufacturing a hydrogen-containing gas accordingto claim 32, further comprising a heat blocking layer with lower thermalconduction characteristics than the first catalyst section providedbetween the first catalyst section and the second catalyst section. 34:The apparatus for manufacturing a hydrogen-containing gas according toclaim 32, wherein an inert member that has no catalytic activity ismixed with the first catalyst section to create a suitable state oftemperature elevation for the first catalyst. 35: The apparatus formanufacturing a hydrogen-containing gas according to claim 32, whereinin a normal operating state, the first catalyst section outlettemperature is the self-ignition temperature. 36: The apparatus formanufacturing a hydrogen-containing gas according to claim 35, whereinif the temperature that is higher between the minimum partial-oxidationtemperature and the dew point temperature of the mixed gas is taken asthe minimum antechamber temperature, and the self-ignition temperatureis taken as the maximum antechamber temperature, the temperature of themixed gas flowing through the antechamber is maintained higher than theminimum antechamber temperature and lower than the maximum antechambertemperature. 37: The apparatus for manufacturing a hydrogen-containinggas according to claim 36, further comprising a desulfurizationapparatus that allows the sulfur compound concentration of the mixed gasintroduced into the catalyst reaction chamber to be 1 ppb or less. 38:The apparatus for manufacturing a hydrogen-containing gas according toclaim 31, wherein the first reforming catalyst is a reforming catalystthat contains at least one of ruthenium and platinum, and the secondreforming catalyst is a reforming catalyst that contains at least one ofnickel, rhodium, and ruthenium. 39: A method for manufacturing ahydrogen-containing gas comprising: a mixing step of mixing, in a mixingchamber, an oxygen-containing gas with a feed gas obtained by mixingsteam with a hydrocarbon fuel; and a reformation step of guiding themixed gas obtained in the mixing chamber into a catalytic reactionchamber via an antechamber provided on the upstream side of thecatalytic reaction chamber and bringing the mixed gas into contact withat least one reforming catalyst and thereby obtaining ahydrogen-containing gas by means of a partial oxidation reaction and asteam reforming reaction, wherein the catalytic reaction chamberincludes a first catalyst section in which is disposed a rutheniumcatalyst and a second catalyst section which is provided on thedownstream side of the first catalyst section and in which is disposed aruthenium catalyst in a state of higher concentration than the firstcatalyst section, the mixed gas is introduced into the catalyticreaction chamber after the temperature of the antechamber has been setto at least a minimum partial-oxidation temperature and below aself-ignition temperature, where the self-ignition temperature is thetemperature at which the mixed gas self-ignites during the advectionperiod required for the mixed gas to move from the mixing chamber to thecatalytic reaction chamber and the minimum partial-oxidation temperatureis the minimum temperature at which the first reforming catalystundergoes the partial oxidation reaction, and the rutheniumconcentration of the first catalyst section is set such that the firstcatalyst section outlet temperature will be at least the temperature atwhich the second catalyst section undergoes partial oxidation and nohigher than the self-ignition temperature in a state in which thetemperature of the antechamber has been set to at least the minimumpartial-oxidation temperature and below the self-ignition temperature;and a step of providing a heat blocking layer with lower thermalconduction characteristics than the first catalyst section between thefirst catalyst section and the second catalyst section. 40: The methodfor manufacturing a hydrogen-containing gas according to claim 39,further comprising a step of mixing an inert member that has nocatalytic activity with the first catalyst section to set the rutheniumcatalyst concentration of the first catalyst section. 41: The method formanufacturing a hydrogen-containing gas according to claim 39, whereinif the temperature that is higher between the minimum partial-oxidationtemperature and the dew point temperature of the mixed gas is taken asthe minimum antechamber temperature and the self-ignition temperature istaken as the maximum antechamber temperature, the temperature of themixed gas flowing through the antechamber is maintained higher than theminimum antechamber temperature and lower than the maximum antechambertemperature. 42: An apparatus for manufacturing a hydrogen-containinggas, comprising: a mixing chamber in which an oxygen-containing gas ismixed with a feed gas obtained by mixing steam with a hydrocarbon fuel;a catalytic reaction chamber into which the mixed gas obtained in themixing chamber is guided via an antechamber and brought into contactwith at least one reforming catalyst and a hydrogen-containing gas isobtained by means of a partial oxidation reaction and a steam reformingreaction, the catalytic reaction chamber comprising, from the inletside, a first catalyst section in which is disposed a ruthenium catalystand a second catalyst section which is provided on the downstream sideof the first catalyst section and in which is disposed a rutheniumcatalyst in a state of higher concentration than the first catalystsection, and the ruthenium concentration of the first catalyst sectionis set such that the first catalyst section outlet temperature will beat least the temperature at which the second catalyst section undergoespartial oxidation and no higher than the self-ignition temperature in astate in which the temperature of the antechamber has been set to atleast the minimum partial-oxidation temperature and below theself-ignition temperature; an antechamber temperature setting means forsetting the temperature of the antechamber to at least a minimumpartial-oxidation temperature and below a self-ignition temperature,where the self-ignition temperature is the temperature at which themixed gas self-ignites during the advection period required for themixed gas to move from the mixing chamber to the catalytic reactionchamber and the minimum partial-oxidation temperature is the minimumtemperature at which the first reforming catalyst undergoes the partialoxidation reaction; and a heat blocking layer with lower thermalconduction characteristics than the first catalyst section providedbetween the first catalyst section and the second catalyst section. 43:The apparatus for manufacturing a hydrogen-containing gas according toclaim 42, wherein an inert member that has no catalytic activity ismixed with the first catalyst section to create a suitable state oftemperature elevation for the first catalyst. 44: The apparatus formanufacturing a hydrogen-containing gas according to claim 42, whereinif the temperature that is higher between the minimum partial-oxidationtemperature and the dew point temperature of the mixed gas is taken asthe minimum antechamber temperature, and the self-ignition temperatureis taken as the maximum antechamber temperature, the temperature of themixed gas flowing through the antechamber is maintained higher than theminimum antechamber temperature and lower than the maximum antechambertemperature.